Boiler construction



I March 9, 1948. c. R. BRIGGS" 4 2,437,347-

BOILER'CONSTRUCTION I Filed June 8, 1944 2 Sheets-Sheet 1 INVENTOR. .ARL R. Bmcaas B AMM Mar ch 9, 1948. R, 'BRIG S 2,437,347

BOILER CONSTRUCTION Filed June 8, 1944 INVENTOR. Cam. Bram-ass 2 Sheets-Sheet 2 Arr? Patented Mar. 9, 1948 BOILER CONSTRUCTION Carl R. Briggs, Mantua, Ohio, assignor of onehalf to John Cunningham, Akron, Ohio Application June 8, 1944, Serial No. 539,353

1 Claim. (Cl. 122250) This invention relates to improvements in water tube steam boilers, and particularly to flash type boilers suitable for the power plant of a, self-propelled tractor, truck, bus, or passenger Vehicle or even for stationary installments.

One object of the invention is to provide a. steam boiler characterized by a novel and efficient water tube arrangement.

A further object of theinvention is to provide a water tube arrangement which is compact and efficient, and is adapted to permit superheating of the steam to any necessary extent.

Another object of the invention is to provide a novel water tube arrangement combined with heating means capable of developing substantially maximum steam pressure in an unusually brief period after starting.

Other objects and advantages will be apparent from a study of the following specification, in conjunction with the accompanying drawings, in which Fig. 1 is a vertical sectional view taken on the line ll of Fig. 2, and Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1, both views showing the principal operating elements of my inproved boiler assembly. Figs. 3 and 4 are horizontal sectional views taken on the lines 3-3 of Fig. 1 and 44 of Fig. 2, respectively.

Before the present invention is described in detail, it is to be understood that such invention is not limited to the details of construction or to the specific arrangement of parts herein illustrated or described, as the invention obviously may take other forms. It also is to be understood that the phraseology or terminology herein employed is for the purpose of description and not of limitation.

Referring now to the drawings, the embodiment of my invention there shown comprises a housing ll, containing in the lower part thereof a Water sediment drum l2, and in the upper part thereof a steam header tank IS. The drum and tank are in communication with each other through a series of water tubes I 4, l5, !6, etc.

The sediment drum I2 is fed from a suitable water supply (not shown) through pipe 27, and steam developed in the steam header proceeds through piping 28 to a power cylinder (not shown) or other suitable application.

As best seen in Figs. 1 and 2, the water heating arrangement consists of a series of burners 29 arranged peripherally around the housing and disposed to throw jets of flame inwardly towards and through the water tube assembly. This pe-- ripheral disposition, including the provision of a novel water tube arrangement now to be described constitutes a most efficient and simple method of developing steam, as Well as superheating the steam after its generation as will appear.

Referring now specifically to the water tubing, where the applied heat is converted to steam, or superheated after such conversion, each individ ual tube includes a portion formed into a Watchspring type spiral, the spiral portions of the various tub-es lying in horizontal planes at spaced levels between the sediment drum I 2 and the steam header tank l3. As best shown in Figs. 1, 2 and 3, tube M has a, lower generally vertical portion Ma, a horizontal spiral portion Mb, and an upper verticaliportion hie. Similarly, tube l 5 has a lower vertical portion Me, an intermediate horizontal spiral portion l5b, and an upper vertical portion 150. Further detailed description is unnecessary, it being apparent that between the sediment drum and the steam header tank there are disposed a plurality of water tubes, each one having an intermediate spiral portion, the radii of the spirals lying in respective horizontal planes at respectively varying heights, and all spirals being Within the combustion zone.

The location of the Water level line is a matter of choice, being controlled at any desired position by a conventional automatic device which may be thermostatic or thermoelectric. Such device is indicated on outline in Fig. 2 as being attached to a bypass water tube 25 extending between the sediment tank l2 and the steam header tank [3. A housing 3! contains a thermosensitive unit which may be a thermocouple having lead wires 32 connected to suitable controls (not shown) in the water supply. The control system need not be shown in detail since various such devices are known to those skilled in the art. Assuming that the water level is being thus maintained at approximately the broken line LL of Fig. 1, it will be apparent that steam generated below and at the level L--L is being superheated at all points above said level and within the combustion space. The combustion space may therefore be'regarded as comprising a steam generating zone and a steam superheating zone, the superheating zone occupying an upper portion of the water tube assembly.

While the steam issuing from any one of the boiler tubes, for example tube M, to the header tank It will not necessarily be superheated to the same extent as the steam from tube 25, since the linear extent of tube 25 within the superheating zone is considerably greater than that of tube I4,

an equilibrium pressure is of course immediately reached in the steam header, which is the resultant of the average pressure from all tubes. A flexible control of the final pressure is achieved by raising or lowering the water level, and consequently respectively decreasing or increasing the total tube footage within the superheating zone.

In the embodiment here shown, the fuel may be a suitable hydrocarbon oil, and the supply of fuel may be automatically regulated, responsive to pressure fluctuations in the steam header, as is 7 well understood by those skilled in the art. The arrangement of the tubes in conjunction with the peripheral disposition of the heating source provides substantially maximum steam pressure in an unusually brief period after starting.

What I claim is:

A steam boiler assembly comprising a housing,

mediate position thereof, the said coiled portions of all said respective tubes being disposed in horizontal planes at respectively spaced vertical levels within said combustion space, water inlet means in communication with said sediment drum, steam outlet means in communication with said steam header tank, and means for maintaining the Water surface Within said tubes at an intermediate level in said combustion space, whereby to define a steam generating zone below said level,

and a steam superheating zone above said level.

a sediment drum within said housing and disposed near the lowermost point therein, a steam header tank above and spaced from said sediment drum, heating means consisting of a plurality of burners arranged peripherally around said housing and inturned towards the space between said sediment drum and said steam header tank to enclose and define thereby a combustion space, a plurality of water tubes extending through said combustion space and individually communicating both with said sediment drum and said steam header tank, each said water tube having a spirally coiled portion at an inter- CARL R. BRIGGS.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS 

